Process of producing dyeings fast to washing on cellulose esters and ethers and the dyed fiber obtained thereby



Patented Jan. 14, 1941 UNITED STATES PATENT OFFICE THEREBY Werner Kirst, Konigstein in Taunus, Germany,

assignor to General Aniline & Film Corporation, a corporation of Delaware No Drawing. Application February 11, 1939, Se-

rial No. 255,865. In Germany February 18,

12 Claims.

The present invention relates to a process of producing dyeings fast to washing on cellulose esters and ethers and to the dyed fiber obtained thereby.

As is known, fast dyeings may be produced on cellulose esters and ethers, by applying to this material an organic compound containing an amino group capable of being diazotized, then diazotizing the compound on the fiber and developing it to the azo-dyestuff by treatment with a coupling component, for instance, p-naphthol.

This invention relates to the production of dyeings fast to washing on cellulose esters or ethers in a much simpler manner by applying to the cellulose ester or ether or dissolving therein an aminonaphthol or a nuclear substitution product thereof, for instance a substitution product containing one or more alkyl groups or halogen atoms, which has in the naphthalene ring at least one free position capable of coupling with diazo-compounds, then diazotizing the aminonaphthol or derivative thereof and causing it to combine with itself by a treatment with an agent neutralizing the acid or having an alkaline action. The combination may be brought about by adding to the diazo-bath an agent neutralizing the acid or having an alkaline action, after the diazotization isfinished, or by passing the diazotized goods through a bath containing one of the said agents.

In this new process a separate heterogeneous coupling component need not be used, since the aminonaphthol applied to the fiber acts simultaneously as diazotizing and coupling component. It'is of great advantage for the dyer that a coupling bath with a separate coupling component, for instance, B-naphthol can be dispensed with. The process permits the production of dyeings fast to washing on effects or knops of cellulose esters or others in fabrics or yarns or shoddy which may contain beside wool staple fiber from regenerated celluloses, when applying dyeing processes which use self-coupling compounds containing sulfonic acid groups, as, for instance, described in my U. S. application Serial No. 212,134, filed June 6, 1938, for Process of producing fast dyeings and the dyed fiber obtained thereby, in .U. S. application Serial No. 231,594, filed September 24, 1938, in the name of Werner Kirst, Wolfgang Alt and Hans Krzikalla for Process of producing fast dyeings and the dyed fiber obtained application Serial No. 221,715; filed July 28, 1938, for Process of producing fast dyeings and the dyed fiber obtained thereby. In this case there is added to the dye-bath usual in these dyeing processes an aminonaphthol of the composition indicated above in the form of a dispersed paste or an alkali salt or an acid salt, the aminon-aphthol being adsorbed practically only on the cellulose ester or ether; the aminonaphthol compound is then diazotized on the fiber and the dyeing developed by self-coupling.

The aminonaphthols may be applied to the fiber in an acid, neutral or alkaline solution. The diazotization is performed with the usual agents; the coupling may be brought about by means of an inorganic base, an inorganic or organic salt of alkaline action or an organic base of alkaline action.

The following examples serve to illustrate the invention, but they are not intended to limit it thereto:

1. 1 kilo of acetate silk is treated for about 1 hour at about 80 C. in a bath containing 50 grams of the sodium salt of 1-amino-.6-naphthol, if desired, in the presence of a. protective colloid, for instance, sulfite cellulose waste liquor or oleylmethyltaur'ine per 30 liters of liquor, rinsed, diazotized in the cold with a solution of 75 grams of sodium nitrite and 150 cc. of hydrochloric acid of 2 B. per 30 liters of water, centrifuged and developed in a cold bath containing per 30 liters of water 80 cc. of ammonia of 25 per cent strength. A black dyeing of very good f-astness to water and washing is obtained.

2. 1 kilo of a mixed fabric from wool and staple fiber from viscose which contains knops or effects of acetyl cellulose is dyed in a bath containing per 30 liters of liquor 50 grams of the sodium salt of the azo-dyestuff 1-(4-amino-2-chlorobenzene azo) -2- amino -5- hydroxynaphthalene -7- sulfonic acid dissolved in water, 80 grams of ammonium sulfate and 8 grams of 1-amino-6- naphthol dispersed with sulfite cellulose waste liquor. The bath is heated to 85 C. and maintained for one hour at this temperature, then cooled, with addition of 600 grams of sodium sulfate, to about 70 C. and the material is further handled for about A: hour. The material is then rinsed, diazotized for /g hour in the cold with a solution of 75 grams of sodium nitrite and 150 cc. of hydrochloric acid of 20 B. with addition of 500 grams of sodium sulfate in 30 liters of water, squeezed and developed at ordinary temperature with 120 cc. of ammonia of 25 per cent strength per 30 liters of Water. A black dyeing is obtained,

the efiects or knops of. acetyl cellulose being likewise dyed a black shade.

The following table serves to illustrate a number of other dyeings obtainable by the invention, for instance, on acetate artificial silk staple fiber:

Iclaim: 1. The process which comprises applying to fibrous materialof the group consisting oi! cellulose esters and ethers an aminonaphthol which has in the naphthalene ring at least one free po- 'sition capable of coupling .with diam-compounds,

then diazotizing the aminonaphthol on the fiber and causing it to combine with itself by an alkaline treatment.

2. The process which comprises applying to fibrous material of the group consisting of cellulose esters and ethers an aminonaphthol which has in the naphthalene ring at least one free position capable of coupling with diazo-compounds, thendiazotizing the aminonaphthol on the fiber and causing it to combine with itself by adding to the diazo-bath an agent having an alkaline action, after the diazotization is finished.

3 The process which comprises applying to fibrous material of the group consisting of cellulose esters and ethers an aminonaphthol which has in the naphthalene ring at least one free position capable of coupling with diam-compounds, then diazotizing the aminonaphthol on the fiber and causing it to combine with itself by passing aaeaeu' the diazotized goods through a bath having an alkaline action.

4. The process which comprises applying to cellulose esters l-amino-fi-naphthol, then diazotizing the aminonaphthol on the fiber and. causing it to combine with itself by an alkaline treatment.

5. The process which comprises applying to cellulose esters i-amino-i-naphthol, then diazotizing the aminonaphthol on the fiber and causing it to combine with itself by an alkaline treatment.

6. The process which comprises applying to cellulose esters l-amino-a-naphthol, then diazotizing the aminonaphthol on the fiber and causing it to combine with itself by an alkaline treatment.

7. Fibrous material oi the group consisting of cellulose esters. and ethers dyed with an azocompound obtainable on the fiber by the process claimed in claim 1.

8. Fibrous material of-the group consisting of cellulose esters and ethers dyed. with an azocompound obtainable on the fiber by the process claimed in claim 2.

9. Fibrous material of the group consisting of cellulose esters and ethers dyed with an azo-' compounds obtainable on the fiber by the process claimed in claim 3.

10. Cellulose esters dyed with the azo-compound obtainable on the fiber by the process claimed in claim 4. V

11. Cellulose esters dyed with the azo-compound obtainable on the fiber by the process claimed in claim 5.

12. Cellulose esters dyed with the azo-compound obtainable on the fiber by the process claimed in claim 6. r v

- WERNER mRST. 

